It's obvious Grandma loved that little girl too.
After watching that, all I can think is what on Earth happened????
I am not the least bit surprised that it "looked" like Casey loved her little girl and could walk the walk, talk the talk when it comes to motherhood. That is what people CAN do when it comes to a mental illness such as Borderline Personality Disorder and a few others that fall under those guidelines.
My dh and I dealt with a mom just like this. After her baby had died, we recieved a page from her journal. She had drawn a picture on it of a bed with a red rose and wrote "life as it is and life as it once was" The head board of the bed was the handle of a dagger and the blade was drawn down the side of the paper, at the end, blood was dripping. She drew this after giving birth the first time (we have that child) but she killed her second one and now has a 3rd in her custody. (death of the 2nd child could not be proven beyond a shadow of a doubt).
Also on this paper she listed about a dozen names, next to each she listed characteristics of each "name",,,,,,,,,one would think of multiple personalities but it is not that because she can play each "character" as she sees fit or who would best fit the senerio at that time. These are all traits we all have within our character, but unlike her, they make us one person.......for her, she is who ever she wants to be at that time,,,,,,,individually.
When her and I talked about her child (before death) she new just as much as I did about being a mom,,,,,,,,,,,,but,,,,,,,,,,,,she could not bond with the child, she did not have the sense or the desire to "make things all better" like most moms do,,,,,,,,she lacked sooooooooooo much in parenting.
I could listen to her "talk about being a mom" then 10 minutes later she could be a giggly little teenager who has fallen in love for the first time, then she could bounce to being a theologist and recite passages from the bible, then she would dye her hair black and play the roll of the wiccan priestess, or turn into Patsy who meek and mild and always looking for love, or Harley the biker chic who liked to dominate in sex and wear black leather. When she died her strawberry red hair black, she is being the "mommy".
She could have made that same type of video as Casey and Caylee's video and FOOLED everyone. That is the way it is with these people.